Fluid detergent products, such as liquids, gels, pastes and the like, are preferred by many consumers over solid detergents. Fluid detergent products may contain surfactants, e.g., anionic surfactants, and one or more solvents, in addition to water. Solvents may provide a variety of benefits: solvents may allow for the formulation of anionic surfactant-rich surfactant systems, particularly for compacted fluid detergents; solvents may adjust the viscosity of a formulation; solvents may allow for the formulation of an isotropic and physically stable formulation; and solvents may allow for the formulation of enzymes, polymers, bleach, chelants, and other ingredients that improve cleaning. Solvents may also be used to formulate stable, shippable, anionic surfactant concentrates, which may be combined downstream with other detergent ingredients to form a final detergent product. Also, some fluid detergent forms, such as fluid unit dose articles, may contain high levels of anionic surfactant and high levels of solvent, such as 30% or more solvent by weight of the total formulation.
Known solvents for use in fluid detergent formulations include 1, 2-propane diol (p-diol), ethanol, diethylene glycol (DEG), 2-methyl-1,3-propanediol (MPD), dipropylene glycol (DPG), oligamines (e.g., diethylenetriamine (DETA), tetraethylenepentamine (TEPA), and glycerine (which may, for example, be used in fluid unit dose articles). However, these known solvents all have significant disadvantages, particularly if used at increased levels, including cost, formulatability, dissolution rate, solubility/stability of film in certain fluid unit dose articles, and potential adverse effects on cleaning and/or whiteness. Thus, there remains an ongoing need to identify new solvents that may allow for the formulation of increased concentrations of anionic surfactants in fluid detergent compositions, particularly compact fluid detergent compositions and concentrated surfactant pastes, and may address one or more of the disadvantages of known solvents discussed above.
A water soluble package formed from a water soluble film containing a substantially non-aqueous liquid composition comprising a surfactant and a primary solvent that is a diol having a Hansen hydrogen-bonding solubility parameter greater than 20, where the hydroxyl groups present in the diol are terminal groups and the distance between these groups is 3 carbon atoms, is known. The liquid composition may also contain a secondary solvent and suitable secondary solvents include glycerine, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, propylene glycol, diethylene glycol, 2,3-butanediol, 1,4-butanediol, 1,3-butanediol, and triethanolamine. This known liquid unit dose product addresses the challenge of preserving the physical integrity and stability of the film and the full capsule.
A concentrated light duty liquid detergent comprising 50 to 68% of a mixture of anionic and non-ionic surfactants suspended in 9 to 18% of an organic solvent, in particular an alkane diol having 3 to 6 carbons and no more than 2 hydroxy groups, is also known.
Also known is a non-aqueous liquid fabric treating composition comprising: a continuous, non-aqueous liquid phase comprising a detersively effective amount of at least one nonionic surfactant; a suspended particle phase, suspended in the non-aqueous liquid phase, comprising a detergent building effective amount of at least one particulate detergent builder salt; and a stabilizer in an amount of about 0.05% to about 1.0% by weight of the composition to inhibit phase separation of the composition, the stabilizer comprising a compound having the formula
where R1, R2, R3 and R4, independently, represent H, lower alkyl of up to 6 carbon atoms, hydroxy-substituted lower alkyl of up to 6 carbon atoms, or aryl, and R1 and R4, together with the carbon atoms to which they are attached, may form a 5- or 6-membered carbocyclic ring, with the proviso that no more than two of R1, R2, R3 and R4 may be aryl.
A solvent-welding process for water-soluble films, characterized in that the solvent comprises a glycol which is a member selected from the group consisting of ethylene glycol; 2, 2-propanediol; 1, 2-propanediol; 1, 3-propanediol; tetramethylene glycol; pentamethylene glycol; hexamethyene glycol, glycerol; 2, 3-butane diol; diethylene glycol; triethylene glycol; and mixtures thereof, and the solvent has a viscosity of from 1.5 to 15,000 mPa·s, is also known.
It has been found that diols, where the hydroxyl groups present in the diol are attached to adjacent atoms, having a Hansen hydrogen-bonding parameter of about 5 to about 20 and a Hansen polarity parameter of about 5 to about 15 are better performing solvents in fluid detergent products. Specifically, it has been found that diols, where the hydroxyl groups present in the diol are attached to adjacent atoms, having a Hansen hydrogen-bonding parameter of about 5 to about 20 and a Hansen polarity parameter of about 5 to about 15 perform better than many existing solvents used in detergent formulations and surfactant pastes, such as 1,2-propylene glycol and dipropylene glycol.